ABSTRACT
In this paper, WO3-Pd2Pt-Pt nanocomposite films were deposited on a single mode fiber as the hydrogen sensing material, which changes its reflectivity under different hydrogen concentration. The reflectivity variation was probed and converted to an electric signal by a pair of balanced InGaAs photoelectric detectors. In addition, the performance of the WO3-Pd2Pt-Pt composite film was investigated under different optical powers, and the irrigating power was optimized at 5 mW. With the irrigation of this optical power, the hydrogen sensitive film exhibits quick response toward 100 ppm hydrogen in air atmosphere at a room temperature of 25 °C. The experimental results demonstrate a high resolution at 5 parts per million (ppm) within a wide range from 100 to 5000 ppm in air. This simple and compact sensing system can detect hydrogen concentrations far below the explosion limit and provide early alert for hydrogen leakage, showing great potential in hydrogen-related applications.
ABSTRACT
BACKGROUND: Human milk oligosaccharides (HMOs) in breast milk contribute to the development of the neonatal microbiota and immune system. However, longitudinal studies examining HMO profiles of Chinese mothers remain scarce. OBJECTIVES: We aimed to analyze HMO profiles, including their composition, concentrations, and changes during lactation, in milk of Chinese mothers. METHODS: A total of 822 milk samples from 222 mothers were collected, of which 163 mothers provided single samples. Samples from the remaining 59 mothers were collected on day 3, day 7, and thereafter every 7 or 14 d until day 168. 24 HMOs were studied using high-performance anion-exchange chromatography. Secretor and nonsecretor status were determined based on Lewis blood types and a defined 2'-fucosyllactose (2'-FL) threshold. RESULTS: Of the 222 mothers, 77% were secretors and 23% were nonsecretors. The longitudinal study involving 59 mothers showed that the total HMOs in secretors were significantly greater than those in nonsecretors during the first 2 wk. Acidic HMOs decreased significantly during lactation and were similar between secretors and nonsecretors. Among neutral HMOs, distinctive differences were observed. Nonfucosylated and α-1-3/4-fucosylated HMOs in nonsecretors were significantly higher than those in secretors during the first month. In contrast, α-1-2-fucosylated HMOs in secretors were significantly higher than those in nonsecretors throughout 168 d. In secretors, 2'-FL concentrations peaked at (mean ± SEM) 3.02 ± 0.14 g/L (day 3) followed by significant decreases. In nonsecretors, 2'-FL concentrations were fairly low throughout 168 d. Of the 24 studied HMOs, only 3-fucosyllactose concentrations increased during lactation in both secretor and nonsecretor mothers. CONCLUSIONS: Our study showed dynamic changes of 24 HMOs in secretors and nonsecretors during lactation and revealed unique features of these HMO profiles in the milk of Chinese mothers. Interestingly, 2'-FL concentrations in secretors were found to be lower than those of Western populations but higher than those of African populations.
ABSTRACT
OBJECTIVE: To investigate the clinical outcome of the repairing of soft tissue defects of foot with reverse island skin flap nourished by vasa vasorum of the sural nerve. METHODS: The skin flap was designed with sural nerve and its vasa vasorum as the pedicle, and was harvested from the posterior crural region based on the size of the wounds. The defects of the foot in eighteen patients were repaired by reverse transplantation of the skin flap. The state of the skin flaps was observed post-operatively. RESULTS: All the skin flaps survived. The biggest skin flap was 10.5 cm x 16.5 cm in size. The donor sites healed well with negligible change in appearance and function. CONCLUSION: Reverse gastrocnemius musculocutaneous flap nourished by sural nerve vasa vasorum was easily procured with high survival rate, and it could be an ideal flap for the repair of soft tissue defect of the foot.
